Expanding and contracting blockers



July 11, 1961 M. F. LACEY EXPANDING AND CONTRACTING BLOCKERS Filed Jan. 19, 1959 FIG. 2

INVENTOR- Michael F. Lacey BY ZM;Q.,. -/2iv ./Z;A

ATTO RN EY S United This invention relates to devices known as blockers, which are employed in the manufacture of rolled strip metal and the like as drums upon which the strip is temporarily wound immediately after being rolled. The new blocker is contractible to permit the coiled strip to be removed easily therefrom after the winding operation is completed. More particularly, the invention provides a wind-up blocker having a contractible drum member formed from a helical torsion spring element which presents a smooth cylindrical outer surface throughout the entire range of its contractibility or expansibility.

Extended lengths of strip or sheet metal are generally wound into coils after being rolled or slit to width, in order to collect the rapidly emerging strip or sheet as efiiciently as possible at the outlet end of the forming machine and to provid for easy handling of the strip. For this purpose, a blocker is commonly located adjacent the forming machine to receive the end of the strip as it emerges and to wrap the strip under tension in tight coils about its rotating drum member. When the entire length of the strip is wound in this manner, the finished coil is removed from the blocker.

Because of the tension the blocker imposes on the strip or sheet as it is being coiled, the completed coil is held so tightly on the blocker that it cannot be forcibly withdrawn without great difficulty. Most blockers have been designed, therefore, so that they can be collapsed after the coil has been wound to permit the blocker to be easily removed from the center of the coil. The conventional collapsible blocker of this type has a winding drum constructed of a plurality of circumferentially narrow segments which extend the length of the drum and are hinged together on hinge axes located in or near the drum surface. These segments are associated with an actuating mechanism in such a manner that the effective drum diameter can be expanded and contracted to a limited extent. However, the winding surface of such a blocker is defined by a plurality of contiguous surfaces each disposed at an angle to the adjoining surfaces, and with gaps between adjoining segments. This design is objectionable because when a strip is wound at least the inner turns of the coil are likely to become creased or otherwise damaged at the angles between the segments, and sometimes such creasing may extend a considerable distance into the coil. As a result the end portion of the strip quite often must be discarded. Also, blockers of this type generally involve relatively intricate expanding and contracting linkages which are the cause of considerable maintenance expense.

One of the most important purposes of the present invention, therefore, is to provide an easily contracted and expanded blocker having a substantially smooth cylindrical drum member so that when a coil is wound even the first turns of the strip are protected from creasing or other damage. Another object of the invention is to provide a blocker of simple design so that it is inexpensive to construct and can be operated with a minimum of maintenance. The invention also aims to provide a blocker of sufiiciently flexible design to permit it to be adapted to the winding of various widths of metal without substantial modifications of its structure. I

Each of these advantages are achieved in the novel blocker of this invention. The new blocker comprises a Patent drum member and means for rotatably mounting the drum member about its longitudinal axis. The drum member is formed from a resilient helical torsion spring element having a plurality of turns or convolutions held close together. At opposite ends of the drum member are a pair of torsion members which engage the respective ends of the spring element. These torsion members are rotatably mounted relative to one another about the axis of the drum member, Turning means are provided for selectively rotating the torsion members relative to one another so that opposed torques are exerted upon the ends of the spring element. This permits the diameter of the drum member to be varied as desired. Releasable locking means are also associated with the torsion members for preventing relative rotation between them to maintain the drum members at the desired diameter.

Preferably, displacement means are associated with the torsion members for moving the ends of the spring element longitudinally relative to each other so that the turns of the spring member are maintained closed as they are expanded or contracted. Additionally the turns of the spring element have their edges configured so that adjoining turns interengage to prevent radial displacement of any one turn relative to any other turn.

A preferred embodiment of the new blocker is described hereinbelow with reference to the accompanying drawings, wherein:

FIG. '1 is an elevation partly broken away and in section of the new blocker;

FIG. 2 is an end elevation of the blocker shown in FIG. 1; and

FIG. 3 is a longitudinal section of a portion of the contractible drum member of the blocker showing some turns of the spring element.

As seen in FIGS. 1 and 2, a spindle 10 extends axially through the entire blocker. At opposite faced-off ends of the spindle 10, axially arranged square holes 11 and 12 are formed to provide means for supporting and positively driving the blocker. In this embodiment, one end portion of the spindle 10 is formed with external threads 14 as shown and the remainder is unthreaded. Since the length of the spindle 10 depends upon the width of the strip being wound and can be varied accordingly, the central portion of the spindle, and of the entire blocker, is shown broken away.

At opposite ends of the spindle 10 a pair of axially arranged circular torsion members 16 and 17 are mounted. The torsion member 1 6 at the unthreaded endof the spindle 10 is of annular construction with an axial bore which receives the end of the spindle and is aflixed thereto by welding or other means. The torsion member 16 comprises an outer flange portion 18 adjacent the end of the spindle and a cylindrical shoulder portion 19 ofreduced diameter extending inwardlytherefrom.

The torsion member 17 at the other end of the spindle 10 includes an outer flange portion 20' and a cylindrical shoulder portion 21 of reduced diameter and has an axial bore forrnedwith internal threads indicated at- 22 These threads 22 are adapted to engage with external threads 23 on the outer cylindrical surface of an annular bushing 24. The bushing 24 also has internal threads indicated at 2-5 which are adapted to engage the external threads 14 formed on the end of the spindle 1U. It" is the function of the bushing 24 to provide an externally threaded mounting means which maybe located at various positions along-the threaded portion of the spindle for supporting the torsion member 17.

Forming the end ofthe bushing 24 nearest theadjacent end of the spindle 10 is an integral circular ratchet wheel 27. A paw-1 30 adapted to cooperate with; the. ratchet wheel 27 is pivotally mounted on a pin 31 which 7 is secured to the outer face of the torsion member 16 adjacent its periphery. The teeth of the ratchet wheel 27 are constructed and the pawl 30 is positioned in such a manner that counterclockwise rotation of the torsion member 17 relative to the bushing 24 (as seen in FIG. 2) is prevented when the pawl is engaged. A lock-nut 33 is threaded onto the end of the spindle to lock the bushing 24 relative to the spindle at the desired longitudinal position. Also, a radial hole 34 is formed in the circumference of the flange portion of the torsion member 17 to receive the end of a turning lever or spanner wrench to aid in the manual rotation of the torsion member 17 relative to the bushing 24.

Positioned around the spindle 10 between the torsion members 16 and 17 is a contractible cylindrical drum member 36, each end of which closely encircles the shoulders 19 and 21 and abuts the flanges 18 and 20 of the torsion members 16 and 17 respectively as shown. Basically, the drum member 36 is of one-piece construction being formed from a single helical torsion spring element 37. The spring element is configured, however, so that each turn interengages with the adjoining turns to prevent relative radial displacement of the turns. For this purpose each turn has one portion 39 which underlies the adjacent portion 40 on the adjoining turn. By this construction the drum member 36 is as a whole made self-supporting even though compressive or expansive forces may be distributed unequally along its length. Each end of the drum member 36 is faced off perpendicular to its axis and the resulting tapered ends 42 and 43 of the spring element 37 are truncated as seen in FIG. 1. Heavy stop pins 45 and 46 project radially from the shoulder portions 19 and 21 of the torsion members 16 and 17 respectively and are abutted by the ends 42 and 43 of the last convolutions of the spring element 37.

In assembling the blocker, the bushing 24 and the torsion member 17 are removed from the threaded end of the spindle 10 and the spring element 37 is located concentrically about the spindle. The end of the spring element is brought up over the shoulder portion 19 against the flange portion 18 of the torsion member 16 with the end 43 abutting the stop pin 45. Then the bushing 24, with the torsion member 17 threaded thereon, is threaded onto the end of the spindle 10 until the shoulder portion 21 and the flange portion 20 of the torsion member 17 engage the end of the spring element, and the end 42 of the spring element is abutted by the pin 46 on the torsion member 17. By further turning the bushing 24 onto the spindle 10, if necessary, the spring element 37 is axially compressed so that its turns are completely closed as seen in FIG. 1. The lock-nut 33 is then threaded onto the end of the spindle and jammed against the bushing 24 to lock it fixedly to the spindle 10.

When it is desired to expand the drum member 36, a turning lever or spanner wrench is placed in the hole 34 and the torsion member 17 is turned clockwise (as seen in FIG. 2) relative to the bushing 24. This causes the stop pin 46 to exert a tangential force on the end 42 of the spring element 37 and that end portion of the spring element is also turned clockwise. However, since, the end 43 of the spring element 37 is abutted by the pin 45 on the torsion member 16, an opposed tangential force is exerted on the opposite end of the spring element. This relative twisting of the ends of the spring element 37 causes its diameter to increase and the drum member 36 therefore expands.

Ordinarily, this expansion would also cause the turns of the spring element 37 to separate. To prevent this, the torsion member 17 is also translated axially along the spindle 10 toward the torsion member 16 as it is rotated, as a result of its threaded engagement with the bushing 24. The direction and pitch of the threads 22 and 23 are chosen so that the torsion member 17 is translated toward the torsion member 16 at a rate which will keep the turns of the spring element 37 closed as 4 they increase in diameter, without jamming the turns together. In this manner, the drum member 36 is expanded While continuously presenting a substantially smooth cylindrical exterior winding surface.

When the drum member 36 is expanded to the desired diameter the helical spring element 37 exerts a torque against the torsion member 17 urging it back to its original position. The pawl 30 and ratchet wheel 27 are provided to lock the torsion member 17 against rotation in a counterclockwise direction relative to the bushing 24. The drum member 36 may be contracted, of course, simply by releasing the pawl 30 from the ratchet wheel 27 and letting the spring element 37 return the torsion member 17 to its original position. As it does so, the torsion member 17 is translated axially in the direction and at the rate to hold the turns of the spring element 37 continuously closed, while permitting the face of the drum member 36 to lengthen in relation to its decrease in diameter.

When the new blocker is placed in operation, it is mounted between a pair of standards in the conventional manner and put in positive-drive engagement with a drive shaft by means of the square driving holes 11 and 12 at each end of the spindle 10. The drum member 36 is then expanded by rotating the torsion member 17 relative to the bushing 24 as described and the metal strip or sheet emerging from the rolls, slitter, or other metal working machine is wrapped about the expanded drum member. Slipping may be prevented between the strip or sheet and the drum member by pulling the first few turns of the strip tightly about the drum. The blocker is rotated at the desired speed such that the strip is wrapped under tension about the drum member 36 in a coil of an ever increasing number of turns. The substantially smooth cylindrical construction of the drum member 36 prevents the inner turns of any other turns of the coil from being deformed in any way. When the entire length of strip is wound, the coil and the blocker are removed from the standards. The pawl 30 is disengaged from the ratchet wheel 27, allowing immediate contraction of the drum member 36, and the blocker is then easily withdrawn from the coil. Depending upon the width of the strip being wound, of course, blockers of various sizes can be employed, the only modification required being that the length of the spindle 10 and the drum member 37 must be varied accordingly.

It is clear that various changes can be made in the design of the above-described embodiment of the new blocker, and it is to be understood that such modifications are fully contemplated by the following claims. For example, the interengagement of the turns of the spring element 37 can be achieved in many ways other than by the overlapping arrangement described, such as by a tongueand-groove arrangement. Also, if desired, the torsion member 16 could be translatably and rotatably mounted about the spindle 10 on a bushing in the same manner as the torsion member 17, so that the drum member 36 could be expanded and contracted from either or both ends of the device. So, too, the ratchet and pawl could be substituted by various other releaseable lock means. Also, the pins 45 and 46 could be attached to the ends 42 and 43 of the spring element 37 so that by rotating the torsion member 17 counterclockwise from its normal position as seen in FIG. 2 the drum member 36 would be contracted.

The new blocker is mechanically simple and inexpensive to make. Yet it is unique in that it always presents a smooth substantially truly cylindrical drum face to receive the strip to be wound on it, regardless of the diameter to which it has been adjusted. It may therefore be used with advantage wherever a blocker is required in the rolling or slitting of sheet or strip, but especially for receiving very thin metal which is readily damaged by angles or other discontinuities on the blocker drum face.

I claim:

1. A contractible blocker comprising a drum member and means for rotatably mounting the drum member about its longitudinal axis, said drum member being formed of a resilient helical torsion spring element having a plurality of convolutions held close together, a pair of torsion members located at opposite ends of said drum member in engagement with the respective ends of the last convolutions of said spring element, said torsion members being rotatably mounted relative to one another about the axis of said drum member, turning means for selectively rotating said torsion members relative to one another such that opposed torques are exerted upon the ends of said spring element thereby permitting the diameter of the drum member to be varied, and releasable locking means associated with said torsion members for preventing relative rotation between them to maintain said drum member at the desired diameter.

2. A contractible blocker comprising a drum member and means for rotatably mounting the drum member about its longitudinal axis, said drum member being formed from a resilient helical torsion spring element having a plurality of convolutions which are configured and held closed so as to present a substantially smooth cylindrical outside surface, a pair of torsion members located at opposite ends of said drum member in engagement with the respective ends of the last convolutions of said spring element, said torsion members being rotatably mounted relative to one another about the axis of said drum member, turning means associated with said torsion members for selectively rotating them relative to one another so that opposed torques are exerted upon the ends of said spring element thereby permitting the diameter of the drum member to be varied, displacement means associated with said torsion members for moving the ends of the spring element longitudinally relative to each other when said torsion members are rotated relative to each other so that the convolutions of said spring element are maintained continuously closed, and releasable locking means associated with said torsion members for preventing relative rotation between them to maintain said drum member at the desired diameter.

3. A contractible blocker comprising a drum member formed from a resilient helical torsion spring element, said spring element having a plurality of convolutions which are configured and held closed so as to present a substantially smooth cylindrical outside surface, a pair of torsion members located at and supporting opposite ends of said drum member in engagement with the respective ends of the last convolutions of said spring element, a spindle extending coaxially through the drum member providing means for rotatably mounting the entire drum member about its longitudinal axis, at least one of said torsion members being in threaded engagement with said spindle so that said torsion members are both rotatable and translatable relative to one another, turning means associated with the torsion members for selectively rotating and translating them relative to one another so that opposed torques are exerted upon the ends of the spring element, thereby permitting the diameter of the drum member to be varied while the convolutions of the spring element are maintained continuously closed, and releasable locking means associated with said torsion members for preventing relative rotation between them to hold said drum member at the desired diameter.

4. A contractible blocker comprising a drum member formed from a resilient helical torsion spring element configured and held closed so as to present a substantially smooth cylindrical outside surface, the convolutions of said spring element having edges which interengage with the edges of the adjoining convolutions to prevent relative radial displacement of the convolutions, a pair of torsion members located at and supporting the ends of said drum member in engagement with the respective ends of the last convolutions of said spring element, a rotatable spindle extending coaxially through the drum member providing means for rotating the entire drum member about its longitudinal axis, one of said torsion members being coaxially fixed to and the other being in coaxial threaded engagement with said spindle, turning means associated with the torsion member which is threaded onto said spindle for selectively rotating and translating the torsion members relative to one another so that opposed torques are exerted upon the ends of the spring element, thereby permitting the diameter of the drum member to be varied while the convolutions of the spring element are maintained continuously closed, and releasable locking means associated with said torsion members for preventing relative rotation between them to hold said drum member at the desired diameter.

5. A contractible blocker comprising a drum member formed from a resilient helical torsion spring element configured and held closed so as to present a substantially smooth cylindrical outside surface, the convolutions of said spring element having edges which underlie and overlap respectively the adjacent edges of the adjoining convolutions to prevent relative radial displacement of the convolutions, a pair of torsion members located at and supporting the ends of said drum member and abutting the respective ends of the last convolutions of said spring element, a rotatable spindle extending coaxially through the drum member providing means for rotating the entire drum member about its longitudinal axis, one of said torsion members being coaxially fixed to and the other being in coaxial threaded engagement with said spindle, manual turning means associated with the torsion member which is threaded onto said spindle for selectively rotating and translating the torsion members relative to one another so that opposed torques are exerted upon the ends of the spring element, thereby permitting the diameter of the drum member to be varied while the convolutions of the spring element are maintained continuously closed, and releasable locking means on the spindle and the torsion member threaded thereon for preventing relative rotation therebetween to hold the drum member at the desired diameter.

References Cited in the file of this patent UNITED STATES PATENTS 2,238,460 Bruestle Apr. 15, 1941 2,255,671 Loehr Sept. 9, 1941 2,534,034 La Brie Dec. 12, 1950 2,818,264 Overstreet Dec. 31, 1957 

